1. Field of the Invention
The present invention relates to a connector terminal and an electric connector that are capable of wiping off foreign material and that are suitable for high-speed transmission.
2. Description of the Related Art
Development in information processing technology and communication technology has dramatically increased the amount of data that is handled by on-vehicle equipment and consumer electric devices. High-speed transmission technology, such as differential transmission (balanced transmission), that can achieve effective transmission of a large amount of data in a short time is used in various electric devices. Therefore, as regards connectors that form part of a transmission path, those that allow impedance matching and that are suitable for high-speed transmission that does not cause distortion in a signal waveform are used.
The basic structure of a connector terminal therefor includes a circuit-board connection portion that is connected to a circuit board and a terminal portion that contacts and is conductively connected with a terminal surface of a mating connector. A “single terminal” that includes only one terminal portion serving as a contact that is connected to the mating connector is generally used.
When foreign material, such as substrate scrap and dust, adhered to connector terminals are interposed between the connector terminals when connecting the connector terminals to each other, poor connection occurs. As means for overcoming this problem, terminal portions of a plurality of terminals including a front terminal and a rear terminal along a fitting direction of a mating connector are known. The front terminal wipes off foreign material adhered to a terminal surface of the mating connector. The rear terminal is fitted to the mating connector following the front terminal and is conductively connected with the terminal surface of the mating connector. Refer to Japanese Unexamined Patent Application Publication No. 2012-69243.
However, the surface area of terminal portions, which become transmission paths, of a plurality of terminals are larger than the surface area of a terminal portion of a single terminal. Therefore, a capacitor component is increased. Consequently, the impedance of the terminal portions is considerably smaller than those of other portions of a connector terminal, as a result of which it becomes difficult to match the impedances. Such a connector terminal is not desirable for, in particular, high-speed transmission of high-frequency signals. For example, it is difficult to meet, for example, high-definition multimedia interface (trade name) standards.